This invention relates to a magnetically recordable photographic film, a recording method and a recording system employing the photographic film, and a camera laboratory system employing the photographic film. The invention encompasses the following first to fifth embodiments.
This invention relates, in the first embodiment, to disposition of a perforation relative to an information recording region of a photographic film having a transparent magnetic recording layer.
This invention relates, in the second embodiment, to a photographic film having a transparent magnetic recording layer, a recording method and a recording system for recording on the photographic film and, above all, to a relation between the photographic film and the perforation in the photographic film and to a recording system especially for camera information.
This invention relates, in the third embodiment, to a recording method for a photographic film provided with a transparent magnetic recording layer, and a photographic film used in the recording method and more particularly to recording of film information.
This invention relates, in the fourth embodiment, to camera and laboratory system and, more particularly, to a camera systems having a magnetic device for magnetic recording by to clock signals in response to the relation between the clock signals and data signals, and to the relation between the pulse frequency and the film transport speed.
This invention relates, in the fifth embodiment, to a camera system and, more particularly, to a camera systems having a magnetic device for magnetic recording.
The related art for the first to fifth embodiments of the invention is summarized as follows.
Related Art in the First Embodiment
A photographic film having a transparent magnetic recording layer has been disclosed in international patent applications having international filing numbers PCT/US 89/04367 and PCT/US 89/04362 and laid open to public inspection internationally (now WO 90/04214 and WO 90/04253). These international patent applications disclose disposition of information recording regions on a photographic film, as shown herein in FIG. 23. FIG. 23 shows, in a front view, a conventional photographic film 100 disclosed in the above referenced international applications. A perforation 125 is formed in a region A defined by a long side 1 of a rectangular photosensitive image area defined by a double-dotted chain line, i.e., frame, and extensions of two short sides m and n of the frame adjacent to the long side 1, that is, in a laterally peripheral region of the frame. Meanwhile CO to C3 and FOO to F29 represent magnetic recording tracks.
Related Art in the Second Embodiment
A photographic film having a transparent recording layer is disclosed in international applications filed under international application numbers PCT/US 89/04367 and PCT/US 89/04362 and laid open to public inspection internationally (now WO 90/04214 and WO 90/04253). In these international applications, a pattern of disposition of information recording regions on a photographic film, as shown herein in FIG. 23, is disclosed. In this figure, there is shown in a front view a conventional photographic film 100 which is disclosed in the above identified international applications, and which includes magnetic recording tracks CO to C3 and FOO to F29, a photosensitive image area (i.e., frame), defined by a double-dotted chain line, and a perforation 125. It is stated in the specification of each of the international applications that information may be recorded on the magnetically recordable tracks CO to C3 by a camera capable of effecting magnetic recording.
There has hitherto been proposed a camera system or a laboratory system in which communication of information between a camera user, a film dealer and a photofinisher or developing laboratory, as well as supervision of information such as supervision of users"" names in the photofinisher, is enabled by magnetic recording on a continuous film.
Such a camera system is disclosed in an international publication WO 90/04253. With the camera system disclosed in this international publication WO 90/04253, when recording the information to be transmitted or supervised as magnetic recording on the continuous film, recording tracks each specifically dedicated to the camera users, film dealers and the photofinishers, respectively are provided in separate portions on the continuous film. On each track, clock signals and data signals are formed as unitary pulse trains in the form of three-bit encoded data (so called xe2x80x9cTri-bit codexe2x80x9d).
The waveform of the three-bit encoded data disclosed in the above international publications is shown herein in FIG. 24, in which rising transition pulse flanks P1A and P2A in each of the rectangular pulses correspond to clock signals prescribing a period t of signals to be recorded. If a pulse width td, which indicates the time since the rising transition pulse flank P1A until the next falling transition pulse flank P1B, is expressed by td=t/3, as shown in FIG. 24(a), the data signal is a binary signal having a logical level of 0. If the pulse width td is expressed by td=2 t/3, the data signal is a binary signal having a logical level of 1.
The waveform of reproduced signals, which are the magnetic recordings made by the signals shown in FIG. 24 and reproduced by a magnetic head, is shown in FIG. 25. In the reproduced signals shown in FIGS. 25(a) and (b), positive peak pulses Q1A, Q2A are produced at time points corresponding to the clock signals, while a negative peak pulse Q1B is produced at a time point corresponding to the data signal. The logical levels of 0 or 1 are determined in dependence upon which of the positive peak pulses Q1A and Q2A lying before and after the negative peak pulse Q1B is closer to the peak pulse Q1B. With the three-bit encoded data, since the clock signals and the data signals are recorded on the same track, the recordings may be transmitted mutually between the user, film dealer and photofinisher despite differences in the film feed speeds between the magnetic devices or the film feed speeds at the camera system, film dealers and the photofinishers. Even when the continuous film is fed in the opposite direction to the recording direction, signals may be deciphered by reference to signal data constituted by bits which are complements to the bits of the three-bit data.
Related Art of the Third Embodiment
There has hitherto been proposed a camera system or a laboratory system in which communication of information between a camera user, a film dealer and a photofinisher or developing laboratory, as well as supervision of information such as supervision of users"" names in the photofinisher, is enabled by magnetic recording on a continuous film, as discussed in connection with the second embodiment mentioned herein above.
Such a camera system is disclosed in PCT international publications WO 90/04253 and WO 90/04214. On each track, clock signals and data signals are formed as unitary pulse trains in the form of three-bit encoded data (so-called Tri-bit code). An explanation for the Tri-bit code signals has been substantially given in connection with the above mentioned second embodiment.
Related Art for the Fourth Embodiment
The related art for the fourth embodiment is as mentioned in connected with the second and the third embodiments and hence the description therefor is omitted.
Related Art for the Fifth Embodiment
The related art for the fifth embodiments is as mentioned in connection with the second and third embodiments and hence the description is similarly omitted.
Problems to be Solved by the Invention
The followings are problems to be sovled by the present invention in its first to fifth embodiment.
Problem to be Solved by the First Embodiment
If the perforation is provided in the region defined laterally of each frame, limitations are imposed for a given film width on the lengths of the magnetic recording tracks within the region defined laterally of a given frame. On the other hand, even if the distance between the frames is increased for augmenting a magnetically recordable region, a sufficiently long continuous magnetic recording track region cannot be provided along the film length in the side edge region of the film in which the perforation is disposed.
It is an object of the first embodiment of the present invention to overcome the above mentioned problems of the known film and to provide a photographic film which may be simultaneously used for magnetic recording, and a recording method therefor.
Problem to be Solved by the Second Embodiment
When recording is made on the magnetic recording tracks C2 and C3, the magnetic head may be impinged against or caught by the edge or end face of the perforation to cause wear or defects to the head. In addition, fluctuation in the film feed speed is produced to lower the reliability of the recorded information. This tendency becomes more pronounced when the photographic film is projected towards the magnetic head in the vicinity of the perforation. It is moreover not desirable to provide recording tracks on the magnetic layer within the photosensitive image area (frame) for recording because flaws tend to be produced due to sliding contact with the magnetic head. Besides, the film feed (or transport) speed within the camera is changed at the outset and at the end of takeup by a factor of two or more times, while being also changed with the type of cameras, the degree of consumption of the batteries or in dependence upon whether the film is taken up automatically, that is electrically, or manually. Despite the fact that the film feed speed is subject to changes or fluctuations, it is required to record as much information as possible with high reliability.
However, when writing in the camera is performed by a method of recording the clock signals and data signals on a track as a unitary pulse train in accordance with clocks of a predetermined period and with the above mentioned Tri-bit code system, considerable limitations are placed on the amount of the information that may be recorded on a recording track associated with a frame length. Further limitations are imposed for taking the allowances into account. The variable nature and fluctuations in the film feed speed may worsen the instability of the recording signals inclusive of the clock signals. This in turn increases the load on devices used at tile photofinisher for reading out the recorded signals. Therefore, this problem also needs to be solved for realizing a magnetic recording system for the photographic film.
It is an object of the second embodiment of the present invention to provide a photographic film and a recording method and system therefor which is free from these inconveniences.
Problem to be Solved by the Third Embodiment
There is no disclosure in the aforementioned publications as to the film region along its entire length in which to properly record the information to the film.
On the other hand, the film transport speed used in general in a camera system or in a laboratory system used in a photofinisher is changed not only from a camera system or a laboratory system to another, but with one and the same camera. That is, since the rotational speed of a film take-up shaft is usually selected on each camera system to a constant value, the film transport speed at the take-up start differs from that at the film take-up end with a ratio of, e.g., 1:3. In addition, the film transport speed is naturally changed with the degree of battery consumption during film take-up.
With the playback signal in the above described Tri-bit code system, since the logical level of 0 or 1 is determined in dependence upon which of the positive peak pulses Q1A and Q2A corresponding to the clock signals is closer to the negative peak pulse Q1B corresponding to the data signals, disposed therebetween, there is a risk of data misreading if the film feed speed is fluctuated by some reason or other between a temporally preceding clock signal and a temporally succeeding clock signal by more than a predetermined amount.
For this reason, there is a risk for the film information, such as film sensitivity, to be misread, in which case photographing is made by a camera on the basis of the misread information, if the camera is of the automatic type.
It is an object of the third embodiments of the present invention to provide a recording method for a magnetically recordable photographic film which is free of the above mentioned problem of the known method, and a photographic film used in the recording method.
Problem to be Solved by the Fourth Embodiment
It is known in general that film transport speeds used at different camera systems or different laboratory systems at developing laboratories differ not only from one camera system or laboratory system to another, but with one and the same camera. That is, since the rotational speed of a film takeup shaft is usually selected to be constant at each camera system, the film feed speed is changed at the takoup start time and at the takoup end time by a ratio of, e.g., 1:3. In addition, the film feed speed is naturally changed with the different degree of battery consumption during film takeup.
With the playback signals in the above described Tri-bit code system, in which the logical level of 0 or 1 is determined in dependence upon which of the positive peak pulses Q1A and Q1B corresponding to the clock signals lying before and after the negative peak pulse Q1B corresponding to the data signal lying closer to the negative peak pulse Q1B, as discussed previously, there is a risk of data misreading if the film transport speed is changed by more than a predetermined amount by some reason or other between a proceeding clock signal and a succeeding clock signal.
On the other hand, since the film transport speed differs by a factor of three times between that at the start of film takeup and that at the end of film takoup, it may occur that, if the recording density should be lowered significantly, the amount of the recording region on the track might be less than the amount of the information to be recorded in each frame. In such case, the frequency of the clock signals cannot be increased for eliminating the problem of shortage of the recording region without producing a problem in connection with the relation with frequency characteristics of the magnetic material employed in the magnetic head.
In view of the above described status of the known systems, it is an object of the fourth embodiment of the present invention to improve the above described conventional camera-laboratory system having the magnetic device for magnetic recording and to provide a camera system which is provided with a magnetic device less subject to errors in signals transmitted between the camera system and the laboratory system despite occasional fluctuations in the film transport speed.
It is another object of the fourth embodiment of the present invention to provide a camera-laboratory system in which a predetermined amount of a recording region may be assured despite fluctuations in the film transport speed as described above and in which a certain operational reliability may be assured for conformity to the frequency characteristics of a magnetic material of the magnetic head.
Problem to be Solved by the Fifth Embodiment
In the recording system by the three-bit encoded data, as disclosed in the above international publication, clock signals and data signals are recorded as a pulse train on one and the same track. Since the camera data usually include data for photographing conditions, such as date and place of photographing and a light stop value, these clock and data signals are naturally recorded during film transport operation which should take place after light exposure of the film.
However, if the totality of data to be recorded by the camera system should be recorded during the film transport operation following the light exposure, the data to be recorded would become voluminous such that it would become necessary to simultaneously consider the film transport speed and the ability of the microprocessor as well as the buffer capacity and frequency characteristics of the magnetic device. However, the corresponding explanation has not been made in the above international publication. For example, the film transport speed in the camera system is low and unstable, such that, in the above described three-bit encoded data system, a problem is raised in that the recording density needs to be set to an extremely low value if it is desired to assure data reliability.
It should also be noted that, after photographing in all of the frames of a continuous film, the film is usually brought to a film dealer or the like for developing the film and printing the frames. If a film loaded on a camera and exposed to light only halfway of its length could be taken out and loaded on another camera, that is, if unexposed film portions could be used up effectively by re-loading the film on another camera so that photographing may be continued, there is no necessity of photographing unnecessary frames in the remaining film portion to make haste for developing film portions already photographed by the first camera, so that it becomes possible to prevent film loss due to unnecessary photographing and wasteful printing. However, there has not been proposed a camera system designed for light exposure of one film by two cameras. In short, the conventional camera system lacks in the degree of freedom as to the photographing sequence which might allow for photographing with frame skipping or photographing of a given image in a particular frame bearing a desired frame number.
It is an object of the fifth embodiment of the present invention to provide a camera system provided with a magnetic device for magnetic recording, in which timing for recording magnetic signals on a continuous film is set so as to enable magnetic recording with a sufficiently high recording density at an appropriate film transport speed for the camera system in use within the performance range of the microprocessor, the buffer and the magnetic device of the camera system.
It is another object of the fifth embodiment of the present invention to provide a camera system having a high degree of freedom as to the particular frames for photographing and the photographing sequence, such as by enabling a continuous film to be exposed to light on two or more camera systems.
Means to Solve the Problem
The following are means for overcoming the problems of the first to fifth embodiments of the invention.
Means to Solve the Problem of the First Embodiment
According to the present invention, the above object in the first embodiment may be accomplished by the following photographic film on which magnetic recording may be made and the recording method therefor.
(1-1) A photographic film on which magnetic recording may be made comprising a film base, a photosensitive layer, and a magnetically recordable transparent magnetic layer, including a perforation being disposed in at least one side edge region of the photographic film lying between adjacent ones of a series of photosensitive image areas on the photographic film, and a magnetic recording track region extending throughout the overall length of the side edge region of the photographic film adjacent to said image area being provided at at least one side edge of the photographic film.
(1-2) A recording method for a photographic film according to above (1-1) on which magnetic recording may be made, comprising the step of magnetically recording information on said magnetically recordable transparent magnetic layer.
Means to Solve the Problem of the Second Aspect
According to the present invention, the above object in the second embodiment of the present invention may be accomplished by the following method for recording on a magnetically recordable photographic film, the recording method and the recording system therefor.
(2-1) A method for recording on a magnetically recordable photographic film comprising a magnetically recordable transparent magnetic layer, said photographic film having perforations only on one side edge thereof, said method comprising the step of recording information by magnetic recording means provided on a camera only on the side edge of the photographic film devoid of the perforations.
(2-2) A magnetically recordable photographic film comprising a film base, a photosensitive layer, and a magnetically recordable transparent magnetic layer, wherein camera information is recorded in a camera only on a side edge of the film devoid of perforations.
(2-3) A magnetically recordable photographic film according to (2-2) in which perforations are provided only on one side of the side edge of the film and in which only the side edge of the film free of the perforations is used as a magnetically recordable track area on which to record the camera information.
(2-4) A recording system for a magnetically recordable photographic film comprising a film base, a photosensitive layer, and a magnetically recordable transparent magnetic layer, said recording system comprising a reading/rewriting device for reading and rewriting information recorded by magnetic recording means provided in a camera.
In the above system, the above information may be rewritten by changing the format.
Rewriting is performed at a recording system provided at the photofinisher and reading as well as rewriting is possible at a constant film feed speed. This renders the recorded information more reliable and stable to improve reliability at the time of subsequent data reading to enable accurate data re-recording for the following reason. The film takeup speed (i.e., film feed or transport speed) in a camera is not necessarily constant but is generally subject to fluctuations due to friction in the film transport system and increases in film takeup bobbin diameter with the progress in the film takeup process. For example, with a constant rotational speed of the takeup bobbin, the film takeup speed is changed gradually from 30 mm/sec to 90 mm/sec using a winder and from 100 mm/sec to 300 mm/sec using a motor drive, as the film takeup process proceeds. For this reason, for reproducing the information recorded by the camera, it is necessary to perform a complex readout processing for accurate reproduction of the recorded information. It would be problematic to incorporate related equipment in the photofinishers and developing lines in the photofinishers. With the recording system of the present embodiment, the above problem may be coped with by rewriting the information in the above described manner. That is, the system of the present invention may be used to rewrite predetermined signals and re-record the rewritten signals on a predetermined recording track under an accurate feeding speed and under predetermined clocks. In this manner, accurate signal recording may be assured and basic data may be constituted for a variety of subsequent processing operations and concomitant additional recording. Preferably the format is changed for rewriting the information. This in turn enables a large quantity of information to be recorded.
According to the present system, the information may be recorded in a compacted form on the predetermined tracks, so that a sufficient amount of data may be recorded only on the recording tracks provided on the side edge of the film which is devoid of perforations, as defined in (2-1), (2-2) and (2-3) above. In addition, further recording regions may be provided for developing and further downstream processing operations.
Means to Solve the Problem of the Third Embodiment
According to the present invention, the object in the third embodiment may be accomplished by the following recording method for the recordable photographic film and to a photographic film therefor.
(3-1) A magnetically recordable photographic film comprising a film base, a photosensitive layer, and a transparent magnetic layer, wherein a set of film information is magnetically recorded on a loading end portion of the film base.
(3-2) A recording method for a magnetically recordable photographic film comprising a magnetically recordable transparent magnetic layer, said method comprising the steps of:
magnetically recording film information on a longitudinal leading end portion of said photographic film, reading said film information, and
magnetically recording the read film information on said photographic film.
Preferably, the leading end portion is a lead part of the film.
(3-3) A magnetically recordable photographic film comprising a film base, a photosensitive layer, and a magnetically recordable transparent magnetic layer, wherein a recording extension adjacent to a lead part of the film is provided within a film width.
(3-4) A recording method for a magnetically recordable photographic film comprising a magnetically recordable transparent magnetic layer, said method comprising the step of recording film information for each photosensitive image area of said photographic film.
(3-5) A recording method for a magnetically recordable photographic film comprising A magnetically recordable transparent magnetic layer, said method comprising the step of recording film information on at least two magnetic recording regions of said photographic film.
Operation of the Third Embodiment
First Sub-Embodiment of the Third Embodiment
By magnetically recording the film information on the longitudinal leading end portion of the photographic film, reading the film information and re-recording the read film information on the photographic film, the film information may be recorded efficiently. For example, when a new film is used, the most crucial film information may be reliably and promptly read at the startup of a film take-up operation on loading the film in a camera. After the film is loaded on the camera, the film in its entirety is taken up and the film information may be recorded in a desired amount at desired positions. In addition, since the film information may be recorded a number of times on succeeding film regions based on the film information read at the leading end of the film, the film information may be checked in the course of subsequent photographing by reading the film information thus recorded in the film regions other than in the leading end portion on the frame-by-frame basis.
Second Sub-Embodiment
Since the recording extension is provided adjacent to the lead part of the film within the film width, a sufficient amount of the film information may be recorded in the leading end of the film, while a spare recording region may be provided therein for additional information. In addition, since the same film information can be recorded a number of times, misreading of the film information may be prevented from occurring. The advantage derived from recording the film information in the leading end of the film has been discussed in connection with the first sub-embodiment of the invention.
Third Sub-Embodiment
By recording the film information in each photosensitive image area (frame) of the photographic film, photographing may be made as the film information can be read frame by frame to check for the film information, while photographing may be started at a desired frame in the film to prevent misreading of the film information.
Fourth Sub-Embodiment
By recording film information in at least two magnetic recording regions in the photographic film, it becomes possible to read the film information two or more times at different positions on the film, so that photographing may be made while checking the film information to prevent misreading of the film information. Most effects may be achieved by recording the film information at the longitudinal leading end of the photographic film or its vicinity.
Means to Solve the Problem of the Fourth Embodiment
The above object in the fourth embodiment, in its first sub-embodiment, of the present invention may be accomplished by a camera system to be used with a continuous film which comprises a photosensitive layer for imaging and a magnetic layer for magnetic recording, said camera system comprising a magnetic device for magnetic recording,
wherein signals for clock information and data for said magnetic recording are formed as a pulse train each having a pulse period t, said clock signals being each defined by a transition pulse flank from a first level to a second level of each rectangular pulse of said pulse train, and said data signals being each formed of a binary signal defined by selection of a pulse width td beginning with one of said transition pulse flanks,
and wherein said pulse period t and the pulse width td are defined as
0 less than td/t 1/4 or 3/4 td/txe2x89xa61
in dependence upon a logical level of a binary signal system.
The object of the fourth embodiment of the present invention, in a second sub-embodiment, is also accomplished by a camera system to be used with a continuous film which comprises a photosensitive layer for imaging and a magnetic layer for magnetic recording, said camera system comprising a magnetic device for magnetic recording,
wherein signals for clock information and data for said magnetic recording are formed as a pulse train each having a pulse period t.
wherein said pulse period t is variable in dependence upon a film transport speed in the camera system.
The above object, in third or fourth sub-embodiments, may also be accomplished by a camera system to be used with a continuous film which comprises a photosensitive layer for imaging and a magnetic layer for magnetic recording, said camera system comprising a magnetic device for magnetic recording,
wherein said continuous film is transported by a winder and a film transport speed ranges between 30 mm/s and 90 mm/s, and
wherein said signals for clock information and data for said magnetic recording are formed as a pulse train, and the frequency f of said clock signals is defined as
50 Hz f 4 kHz:
Also, the present invention may be accomplished by a camera system to be used with a continuous film which comprises a photosensitive layer for imaging and a magnetic layer for magnetic recording, said camera system comprising a magnetic device for magnetic recording,
wherein said continuous film is transported by a motor drive and a film transport speed ranges between 100 mm/s and 300 mm/s, and
wherein signals for clock information and data for said magnetic recording are arranged as a pulse train, and the frequency f of said clock signals is defined as 150 Hz f 12 kHz.
The above object of the fourth embodiment of the present invention may also be accomplished in a fourth sub-embodiment, by:
a laboratory system to be used with a continuous film which comprises a photosensitive layer for imaging and a magnetic layer for magnetic recording, said camera system comprising a magnetic device for magnetic recording,
wherein said continuous film is transported by a motor drive and a film transport speed ranges between 200 mm/s and 500 mm/s, and
wherein signals for clock information and data for said magnetic recording are arranged as a pulse train, and the frequency f of said clock signals is defined as
300 Hz f 20 kHz.
Means to Solve the Problem in the Fifth Embodiment
The above objects of the present invention may be accomplished by a camera system used with a continuous film having a photosensitive layer for imaging and a magnetic layer for magnetic recording, said camera system comprising a magnetic device for magnetic recording,
wherein, on loading said continuous film, checking said continuous film and, if magnetic signals fail to have magnetic signals have already been recorded on said continuous film and, if magnetic signals fail to have been recorded, thereon prescribed magnetic signals are recorded on the continuous film during prewinding of the film.
Among the magnetic signals to be recorded during prewinding for initial formatting, there are data not relevant to photographing conditions for each frame, such as, for example, frame number data allocated to each frame, clock signals or data concerning, camera identification number or camera owner code, etc.
Operation of the Fifth Embodiment
By initial formatting upon loading a new film, frame numbers etc. may be set. Also, by previously recording the data irrelevant to photographing conditions during prewinding, the data to be recorded during film transport following light exposure may be reduced in volume. In this manner, the performance of the microprocessor, the buffer or the magnetic device etc. may be selected to be lower than a predetermined range while the film transport speed may be maintained at a speed suitable for the camera system.
By having the frame number, to be allocated to each frame, recorded during the prewinding, it becomes possible to photograph on a desired frame by subsequently designating the frame number at the camera system without obeying the frame arraying sequence on the film. Also it becomes possible to photograph on a film with the use of two or more cameras. As a result, it becomes possible to have a plurality of films having different ASAs loaded alternately in one and the same camera for sequentially photographing at desired frame positions.
Meanwhile, the frame number may be set on the basis of read-out positions of the perforations, or as a function of the prewinding speed, although this complicates the construction of the apparatus to some extent. The latter arrangement may be adopted for a film devoid of perforations or a usual film having a series of perforations.
Initial formatting includes the recording of data, such as clock signals, camera identification numbers, etc. in addition to the above mentioned setting of the frame number and frame positions. During the initial formatting, setting for calculation of light exposure conditions is made within the camera system on the basis of data previously recorded on the film, such as ASA. Although the film used in the camera system of the present embodiment is assumed to be a 35 mm film, this is not limitative of the present invention.
The following descriptions are provided for the preferred embodiments in the first to third embodiments of the present invention.
Preferred Embodiments of the First Embodiment
The aforementioned perforation needs to be provided in at least one side edge region of the film lying between neighboring ones of a series of photosensitive image areas i.e., frames on the film. However, if necessary, the perforation may be provided in both side edge regions of the film.
The magnetic recording track region is provided at least throughout an overall transverse length of a side edge region adjacent to the associated frame. If necessary, the magnetic recording track region may reach a boundary zone between the adjoining frames along the film length. If the perforation is provided only at one side edge of the film, it is only sufficient if the magnetic recording track region at the opposite side edge of the film to be of the same length as the first stated magnetic recording track region for the same frame.
A sole magnetic recording track or two or more magnetic recording tracks parallel to one another are formed in the magnetic recording track region(s) in the side edge region(s) associated with a given frame. If necessary, the track(s) may be divided into two sections along the film length.
The magnetic recording track region(s) may also be formed in partial superposition or overlap with the photosensitive image area (frame). However, if a flaw is likely to be produced on contact with a magnetic head, it is desirable to avoid recording on the overlapping region(s) with the frame, provided that sufficient recording may be made in the side edge region(s). If the side edge region(s) is insufficient for recording, it is desirable to make recording on the overlapping track region(s) beginning with those tracks lying closer to the lateral side of the frame. Two or more tracks may be provided parallel to one another along the film length in the magnetic recording track region(s) which overlap the frame. If necessary, these tracks may be divided into two or more sections along the film length.
The photographic film of the present embodiment includes a photosensitive layer on one side of a film base and a magnetically recordable transparent magnetic layer on the other side of the film base. The surface of the transparent magnetic layer may also be coated with a protective layer exhibiting anti-static and lubricating properties.
The transparent magnetic layer needs only to be so transparent that the photographic film of the present embodiment provided with the magnetic layer may be used as a photographic film. It is sufficient if the transparent magnetic layer is formed of a transparent base layer having fine magnetic bodies dispersed at a lower density.
The photographic film of the present embodiment may also be accommodated in a cartridge and loaded in this state in a camera for photographing.
Preferred Embodiments of the Second Embodiment
The information to be recorded on the side edge of the film devoid of perforations by magnetic recording means provided on the camera includes the presence or absence of stroboscopic illumination, the type of light source, the type of lens, day and time of photographing, presence or absence of light exposure, title, film sensitivity, camera used for photographing, photographer, shutter speed, light exposure time, size of diaphragm and the like, which are termed collectively as camera information.
For rewriting the information recorded on the side edge of the film devoid of perforations (camera information), the above information is read using the recording system of the present embodiment and preferably the read information is recorded on the side edge of the film using a constant feed speed such as the film feed speed or the feed speed of the magnetic recording means such as a magnetic head. In this manner, the clock period may be made constant to assure accurate data recording. If the magnetic recording means having an accurate film transport system provided, e.g., at a photofinisher is used, the read-out information may be recorded in a region other than the side edge of the film devoid of perforations. For recording the read-out information in the same region, it is only sufficient to overwrite the recorded information without erasure. The information recorded for rewriting may be the same information as the information recorded in the camera, a selected portion of the information, or the information added with a new piece of information.
Upon rewriting, the format may be changed to one adapted to the recording system at the photofinisher for effecting recording. Sufficient redundancy is required of the recording format for the camera information in the camera because the recording format is prescribed in consideration of diversities of the types of cameras, changes in the feed speeds and fluctuations in the feed speeds. In contrast thereto, a format of a higher density may be set at a high precision recording system for the laboratory.
Thus a sufficient amount of the recording capacity may be maintained even if the region for tracks used for recording is limited to a side edge region or its vicinity.
The format may be changed with respect to tracks designated for specific information, track width, track pitch, track position, the number of recording fields in a track or clocks.
Preferred Embodiments of the Third Embodiment
The film information may be enumerated by, for example, film sensitivity, number of frames, film types, day of production, time limit of use, production number and the like.
First Sub-Embodiment
Magnetic recording of the film information at the longitudinal leading end of the photographic film may be made during the film production process.
Reading of the film information may be made by magnetic recording means, such as a magnetic head, provided in a camera. Rerecording of the read information of the photographic film may be made by, for example, the magnetic head of the camera.
Second Sub-Embodiment
Preferably, the extension for recording is provided so as to be in the area of a size enough to provide a track, along the longitudinal direction of the film, corresponding to a magnetic recording track provided at a side edge adjacent to a frame.
The photographic film of (which can be used in) the present embodiment includes a photosensitive layer formed on one side of the film base and a magnetically recordable transparent magnetic layer formed on the other side of the film base. The surface of the transparent magnetic layer may be coated with a protective layer exhibiting anti-static and lubricating properties.
As for the transparent magnetic layer, it is only sufficient if the transparent magnetic layer is transparent enough to permit the photographic film of the present embodiment to be used as a photographic film. It is also sufficient if the magnetic layer has fine magnetic particles dispersed in a transparent base layer at a lower density.
The photographic film of the present embodiment may be loaded and used in the camera in the state in which it is accommodated in a cartridge.
Third Sub-Embodiment
Recording is preferably made in a magnetic recording region along a side edge (or edges) of the film.
Recording of the film information is made by magnetic recording means, such as a magnetic head, provided in the camera.
The film information may be that obtained upon reading the information recorded at the longitudinal end of the photographic film.
Fourth Sub-Embodiment
Most preferably, recording is made at the longitudinal leading end of the photographic film, and at a side edge of the film adjacent to the first and/or second frame. If necessary, recording may be made frame by frame, in which case recording is made at a side edge of the film adjacent to each frame.
The film information may be recorded by magnetic recording means, such as a magnetic head, provided on the camera.
The film information may be that obtained upon reading the information recorded at the longitudinal leading end of the photographic film.
Meanwhile, the photographic film employed in each of the methods of the present invention is not limited to that of the second embodiment of the invention. The perforation may be provided at one of or both side edges of the film. The perforation may also be provided at a side edge lying between the frames.